Printing mechanism having a rim of rotating typelevers

ABSTRACT

A TYPE BAR ASSEMBLY CONTINUOUSLY ROTATING BELOW A PLATEN, WITH THE PRINTING POINT LYING ON OR IN THE DIRECT PROXIMITY OF THE EXTENDED CENTER LINE OF THE AXIS OF THE ASSEMBLY, IT IS PROVIDED THAT THE PRINTING PLANE IS ARRANGED IN FRONT OF THE CENTER LINE OF THE AXIS WHEN VIEWED IN THE PRINTING DIRECTION, AND THAT THE DISTANCE THEREBETWEEN IS DETERMINED BY THE MAXIMUM ADMISSIBLE RELATIVE SPEED BETWEEN THE FIRMLY ARRANGED PLATEN AND THE TYPE BAR MOVEMENT, AT THE MOMENT OF PRINTING.

O United States Patent 1 1 1 1 3,727,741

Galaske 1 Apr. 17, 1973 [54] PRINTING MECHANISM HAVING A 2,127,507 8/1938 Fuchs .197/s3 RIM 0 ROTATING TYPELEVERS 2,139,700 12/1938 Slavin..... 197/14 x 2,369,433 2/1945 Casey ..197/18 X Inventor: F9lker Galaske, Pforlhelm, 2,547,046 4 1951 Salmon ..197 53 many 3,289,805 12/1966 Kleinschmidt et al.... ..197/l8 3,417,847 12/1968 Fleischer et a1. ..l97/18 [73] Assrgnee: International Standard Electric Cor- 36299-49- M 102%,, Bugging-lg "1977118; 12911111911, New York, 3,355-001 ll/l967 Reed etal. ..197/l8 [22] Filed: Aug 22, 1963 Primary Examiner-Edgar S. Burr Attorney--C. Cornell Remsen, Jr., Walter J. Baum, PP N04 754,578 Percy P. Lantzy, Philip M. Bolton, Isidore Togut and Charles L. Johnson, Jr. I

30 F 1 A lication Prior-1 Data l 1 m W 57 ABSTRACT Sept. 19, 1967 Germany ..P 15 37 440.0

a type bar assembly contmuously rotatmg below a platen, with the printing point lying on or in the direct (g1 "197/155; proximity 0f the extended center line of the axis of the [58] Fije'ld 197/18 53 assembly, it is provided that the printing plane is arranged in front of the center line of the axis when viewed in the printing-direction, and that the distance [56] References Cited therebetween is determined by the maximum admissi- UNITED STATES PATENTS ble relative speed between the firmly arranged platen and the type bar movement, at the moment of print- 304,463 9/1884 Sheehy .;.....197/18 i 871,145 11/1907 Richards ..197/l8 1,864,088 6/1932 Morton ..178/27 11 Claims, 4 Drawing Figures PATENT ED APR 1 71973 SHEET 1 UF 3 I'NVENTOR FOL/(ER 64 LA s a ATTORNEY PATENTED APR I 7 I975 sum 2 0? 3 Fig. 3

INVENTOR Fol-ken GALASKE ATTORNEY PAIENIED APR 1 71973 SHEET 3 OF 3 INVENTOR F0 4 KZR qALA 5K5 ATTORNEY PRINTING MECHANISM HAVING A RIM OF ROTATING TYPELEVERS CROSS-REFERENCE TO RELATED APPLICATIONS This application is related to co-pending U.S. application Ser. No. 624,527, filed Mar. 20, 1967, now issued as US. Pat. No. 3,417,847, and entitled Printing Mechanism Having a Rim of Rotating Typelevers."

BACKGROUND OF THE INVENTION The subject matter of the cross-reference is a printing mechanism-for effecting serial data recording, in which the printing device consists of an assembly of type bars arranged radially in relation to an axis of rotation, with the type bars being individually selected and caused to hit against a printing support. A main feature resides in the fact that the type bar assembly rotates at a constant speed, and that the axis of rotation of the type bar assembly, with respect to the printing support,

is arranged in such a way that an extended center line of the axis intersects with the normal at the printing point, and that this point of intersection is lying in or approximately in the printing plane.

This permits the flying selection and printing of a desired type out of the rotational movement, and the relative movement, between the stationary printing support and type which is in rotation is practically reduced to zero at the moment of printing.

In manufacturing, this arrangement restricts the number of type bars, and thus a requirement for an expanded character repertoire including all possibilities would in turn require a double or multiple character occupation of each type and corresponding type bar. This necessitates a shifting of the type bar assembly to effect proper selection of a desired character which should be avoided if possible.

SUMMARY OF THE INVENTION It is therefore an object of this invention to permit a certain relative movement between the printing sup port and the type according to this inventive principle present invention, is characterized in that the printing plane is lying in the printing direction in front of the extended center line of the axis of rotation of the type bar assembly, and in that the distance between the printing point and the extended center line of the axis is restricted by the maximum permissible relative speed between the stationary printing base (platen) and the rotating type bar at the moment of printing.

A feature of this invention is that it is now possible to enlarge the effective diameter of the type bar assembly to such an extent that the number of type bars which may now be accommodated with one character per bar, is sufficient for the vast majority of cases.

BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of the invention will now be explained in detail in conjunction with FIGS. 1 to 3 of the accompanying drawings, in which:

FIG. 1, partly in a sectional view taken on line l-I of FIG. 2, shows a side view of the printing mechanism according to the invention at the moment of a printing process;

FIG. la, shows the printing mechanism of FIG. 1 in a section taken on line ll-II with one type bar which has been selected for the printing purpose;

FIG. 2 shows the printing mechanism according to FIG. 1 in a top view; and

FIG. 3 shows the type bar selecting station in a schematic detailed representation.

DESCRIPTION OF THE PREFERRED EMBODIMENT The printing mechanism as shown in FIGS. 1 and 2 substantially corresponds to the fundamental concept of the cross reference, with one difference being that the printing point is no longer lying in the proximity of the extended center line of axis 10a of the type bar assembly 3, but is arranged in the printing direction at the distance x in front of the center line. By the radius of the ring axis 13 acting as the type bar bearing, which is now correspondingly enlarged by the amount x, it is possible to include a considerably greater number of type bars in one type bar assembly than heretofore. The limitations to this number are determined in part by the radially extending guide straps between the individual type bars which, for reasons of stability for example in the direction of the center of rotation, must be of a predetermined strength (thickness). Other differences and improvements over the cross reference include adoption of unitary type bar construction with the type bars 14 having tab extensions 14b for effecting the printing operation, selection of type bars 14 for the printing operation via the free ends 14a thereof as opposed to selection via transfer levers, and a type bar assembly plugin mounting arrangement which permits demountable coupling of the type bar assembly 3.

Referring to FIG. 1, the printing element including the type bar assembly 3 is swivelled with respect to the vertical so as to form respective thereto an angle a with the extended center line of the axis of rotation of the type bar assembly. It is thus achieved that for an given type bar length, the printing is effected at a point of the platen circumference which is still within a favorable viewing angle. The printing element is designed as a carriage device which, via slide and guide rollers 5, is mounted to the frame 4 at three points (FIG. 2) on slide bars 6. The bars 6 extend in parallel relation to the platen 1, and the carriage device is displaceablyv supported in a formlocking manner and alongside the platen 1.

At approximately the center of the carriage device, and on a bearing or pivot pin 10 which is firmly arranged within the frame 4, a gear 9 is rotatably mounted. Gear 9, which is secured and prevented from being displaced in the axial direction, is provided in the axial direction with a guide shaft 9a, having an adjusting wedge 9b in the lower portion thereof. The gear 9, via helical gearing, meshes with drive gear 8 which, in turn, is pivoted in the frame 4, and on a profiled shaft 7 extending parallel to the platen l, is rotated continuously in the operating condition by driving means not core 11 (not shown in FIG. 1) which, in the. axial direction, is provided with a sleeve-like supporting shaft 1 la having radially directing supporting flaps 1 1b. The supporting or carrier shaft 11a has an internal diameter which is adapted to the guide shaft 9a, and is provided with an indentation corresponding to the adjusting wedge 9b. The supporting flaps 11b are provided at their ends with bores which act as the bearing for the ring axis 13 which serves as the center point of rotation for the type bars 14. The type bars 14 on the ring axis 13 are guided by two plate-shaped slotted disks 15a and 15b. These disks have the same shape and are mounted in mirror-image manner with respect to one another to the core of the carrier with the aid of screws 16 as shown in FIG. 2. Disks 15a and 15b provide radially extending guide slots equally spaced apart and designed to maintain a narrow continuous rim portion which has a slight incline to provide the disks with greater stability. In addition, the upper disk 15a acts as a support for the type bars 14 when they are in a nonprinting position. The type bars 14 include a disk-like center portion which provides reliable guiding prior to, during, and after printing, because the transverse forces require an exact guidance of the type bars. The printing-end of the type bar is tapered to a width which, depending on the material, enables a flexible sideways motion of the upper portion of the type bar. This end of the type bar includes a tapered snug 14a, below which the type 140 is arranged in the conventional manner. Each type bar 14 includes an extension 14b which, in case of selection by cam portions 21 and 22 (FIG. 2) mounted on the frame 4, can cause it to hit the platen and be returned to normal thereafter.

Accordingly, type bar assembly 3 is capable of being plugged onto the guide shaft 9a as one unit as shown in FIG. 1. The adjusting wedge 9b in connection with the corresponding indentation provided in the carrier shaft 11a provides a true angular position in relation to the zero condition, such that no special balancing or adjustment is required when assembling or replacing a type bar assembly. With the aid of'a screw 12 (FIG. 2) the slipped-on type bar assembly 3 is connected in a form-locking manner to the guide shaft 9a.

Above the plane of rotation of the type bar assembly 3 there is arranged a guide ring 17 which is fixed by screws 18 to the frame 4. Its internal diameter is designed so that it covers the type bars 14 within the range of the snug 14a. It acts as a contact safety device (i.e., protection against electric-shocks) and retains the type bars which have not been selected for printing inthe normal circular path. Since the centrifugal force acting upon the type bars normally provides sufficient bearing or contact pressure on the rim portion of the disk, the guide ring prevents shocks or vibrations from causing an uncontrollable self-motivated movement of the type bars which could lead to a selecting process. Within the range of a type bar selecting station 24, which is l80 from the printing point, the guide ring 17 is provided with a cutout portion 19 within which the selected type bar 14, in the sense of rotation according to FIG. 3 as indicated by the arrow, is deflected into the path indicated by the dot-and-dash-line. Any suitable mechanical or electromechanical device or means, including that contained in the disclosure in the crossreferenced patent, may be used as station or selecting means 24 for type bar selection. A deflector or switch member 'provides a smooth transition into the upper circular path wherein the selected type bar 14 is supported by the bottom edge of its snug 14a riding on the upper side of the guide ring 17.

The guide ring 17, in accordance with the rotation of the type bar assembly 3, brings the selected type bar into the range of the printing cam 21a. The ring 17, as shown in FIGS. 1, 1a and 2, is provided in the printing zone with upwardly and downwardly drawn edges or rim portions, these two marginal edges being designed as respectively an advance cam 17a and a follow-up cam 17b. These cams are lying within the circular range of the snugs 14a. The advance cam 17a brings the selected type bar 14, as in FIG. la, by continuous acceleration into the shown position wherein the type bar extension 14b in a smooth and shockless manner engages the printing cam 21a. By this engagement the type bar, during further rotation of the type bar assembly 3, is further accelerated and suddenly lifted upwardly to just short of the printing point. The last portion of the travel, before hitting the recording medium 2, is in a free flight condition. The selected type bar 14 with its extension 14b rebounds from the printing operation, and due to the continuous rotational movement of the type bar assembly 3, will follow the guidance of the resetting cam 21b and the cam portion 22. The centrifugal force acting upon the type bar causes the type bar to follow the resetting cam 21b. The follow-up cam 17b is designed to be a direct continuation of the resetting cam 21b, and the type bar snug 14a engages cam 17b as soon as the type bar extension 14b is released by the cam 21b. The type bar 14 is reset or returned in a shockless manner in course of the further rotation within the range of a second recess 17d which permits the type bar to return to the quiescent circular path. A restoring flap projects upwards out of the recess 17d to ensure the resetting of the type bar to the normal path, out of which there may then be effected a new selection in the'way described hereinbefore.

For high reliability during the selecting process by the station 24, it is necessary that all type bars 14 pass the selecting station at equal height. This would require the upper slotted disk 15a, whose edge serves as a support for the type bars, to be completely plane. This is a costly requirement which can be avoided according to FIG. 3 by providing, in the direction of rotation, an aligning cam 23 in front of the station 24. The cam 23 by its slight pitch lifts all type bars 14 slightly off the disk, thereby providing equal conditions for all type bars within the range of action of the selecting station 24.

What is claimed is:

1. An improved printing mechanism for serial data recording, of the type including a type bar assembly (3) rotating at a constant speed in which the type bars (14) are pivotably mounted and arranged radially in relation to the axis of rotation of the assembly (3) and in which the individual type bars (14) selected for the printing operation are urged from the normal rotation within a predetermined angular position and perform theprinting movement toward the axis of rotation in order to strike the platen at the printing point, wherein the improvement comprises:

a. the point on the platen surface at which a selected type bar strikes in the printing operation being displaced a predetermined distance (X) from an extended center line (a) of the axis of rotation of the type bar assembly (3);

b. each of the type bars (14) having unitary construction including a disk-shaped pivotable center portion having a tab extension (14b) thereto and an arm extension carrying the type (14c) proximate the free end (14a) thereof;

c. a cam portion (21) positioned relative to the rotating type bars (14) for engaging said tab extension (1411) of the type bars (14) selected for a printing operation, said cam portion (21) including a printing cam (21a) which by way of said engagement with said tab extension (14b) provides an acceleration of the free end (14a) of each selected type bar (14) to a point proximate the printing point, and further including a resetting cam (21b) arranged relative to said printing cam (21a) in the direction of rotation for directing a selected type bar, by way of the tab extension (14b) thereof, back to the normal rotation following a printing operation; and

d. means (17, 17a and 20), concentrically arranged about the type bar assembly above the free end 14a) of the type bars (14), for positively acting on the free end (14a) of each selected type bars (14) to bring the tab extension (14b) thereof into engagement with said cam portion (21 2. A printing mechanism according to claim 1 wherein the type bar assembly (3) includes a supporting shaft (11a) by way of which the type bar assembly (3) is demountably coupled to the drive means (7,8,9).

3. A printing mechanism according to claim 2 wherein the axis of rotation of the type bar assembly (3) is swivelled by a predetermined angle (a) with respect to the vertical in compensation for the location of the printing plane being displaced from the extended center line (10a) of the type bar assembly axis of rotation in order to present the optimum viewing angle.

4. A printing mechanism according to claim 2 wherein the type bars (14) are arranged on a ring axis (13) and are guided by two plate-shaped slotted disks (a, 15b) arranged in mirror-image relationship to one another and wherein said disks are connected to a common carrier (.1 la, 1 lb).

5. A printing mechanism according to claim 4 wherein said slotted disks (15a, 15b) are arranged one on top of the other and have a continuous outer rim portion which is inclined with respect to the axis of said type bar assembly and wherein said rim portion, in the case of the upper slotted disk (150), provides support for the type bars (14) when in the normal rotational plane.

6. A printing mechanism according to claim 5 wherein for each type bar (14) said tab extension (14b) is arranged relative to said arm extension such that in each operational position of the type bar (14), the tab extension (14b) projects out of the lower slotted disk 15b).

7. A printing mechanism according to claim 2 wherein said means for acting on the free end (14a) of the selected type bars (14) include a guide ring (17) arranged around the periphery of the type bar assembly (3) and having an advance cam (17a) operating on the free end (14a) of the selected type bars (14.) in the course of rotation of the assembly (3) to lift a selected type bar 14) intoengagement with said cam portion 8. A printing mechanism according to claim 7 wherein said guide ring (17) is arranged above the plane of rotation of the type bar assembly (3), with the inside edge thereof extending over the free ends (14a) of the type bars (14), said guide ring (17) being provided with a cut-out portion (19) located diametrically opposite the printing point and which in the direction of rotation is provided with a deflecting member (20), said guide ring (17) being further provided with a recess (17d) which, respective to said cut'out portion (19), is staggered by approximately 90 opposite to the direction of rotation, said recess (17d) being covered by a restoring flap (170) which is inclined in opposition to the direction of rotation.

9. A printing mechanism according to claim 7 wherein said guide ring (17) further includes a followup cam (17b) operatively arranged relative to said advance cam (17a) in the direction of rotation and wherein said advance cam (17a) and said follow-up cam (17b) lie within'the rotational range of the type bar free ends (140) a predetermined rotational distance to either side of the printing point.

I 10. A printing mechanism according to claim 9 wherein'said cam portion (21) is arranged below the printing point and includes a printing cam (21a) and a resetting cam (21b) arranged relative to said printing cam (21a) in the direction of rotation, the cooperation of the type bars (14) with said guide ring (17) and said cam portion (21) being such that by the guiding of the 

1. An improved printing mechanism for serial data recording, of the type including a type bar assembly (3) rotating at a constant speed in which the type bars (14) are pivotably mounted and arranged radially in relation to the axis of rotation of the assembly (3) and in which the individual type bars (14) selected for the printing operation are urged from the normal rotation within a predetermined angular position and perform the printing movement toward the axis of rotation in order to strike the platen at the printing point, wherein the improvement comprises: a. the point on the platen surface at which a selected type bar strikes in the printing operation being displaced a predetermined distance (X) from an extended center line (10a) of the axis of rotation of the type bar assembly (3); b. each of the type bars (14) having unitary construction including a disk-shaped pivotable center portion having a tab extension (14b) thereto and an arm extension carrying the type (14c) proximate the free end (14a) thereof; c. a cam portion (21) positioned relative to the rotating type bars (14) for engaging said tab extension (14b) of the type bars (14) selected for a printing operation, said cam portion (21) including a printing cam (21a) which by way of said engagement with said tab extension (14b) provides an acceleration of the free end (14a) of each selected type bar (14) to a point proximate the printing point, and further including a resetting cam (21b) arranged relative to said printing cam (21a) in the direction of rotation for directing a selected type bar, by way of the tab extension (14b) thereof, back to the normal rotation following a printing operation; and d. means (17, 17a and 20), concentrically arranged about the typE bar assembly above the free end (14a) of the type bars (14), for positively acting on the free end (14a) of each selected type bars (14) to bring the tab extension (14b) thereof into engagement with said cam portion (21).
 2. A printing mechanism according to claim 1 wherein the type bar assembly (3) includes a supporting shaft (11a) by way of which the type bar assembly (3) is demountably coupled to the drive means (7,8,9).
 3. A printing mechanism according to claim 2 wherein the axis of rotation of the type bar assembly (3) is swivelled by a predetermined angle ( Alpha ) with respect to the vertical in compensation for the location of the printing plane being displaced from the extended center line (10a) of the type bar assembly axis of rotation in order to present the optimum viewing angle.
 4. A printing mechanism according to claim 2 wherein the type bars (14) are arranged on a ring axis (13) and are guided by two plate-shaped slotted disks (15a, 15b) arranged in mirror-image relationship to one another and wherein said disks are connected to a common carrier (11a, 11b).
 5. A printing mechanism according to claim 4 wherein said slotted disks (15a, 15b) are arranged one on top of the other and have a continuous outer rim portion which is inclined with respect to the axis of said type bar assembly and wherein said rim portion, in the case of the upper slotted disk (15a), provides support for the type bars (14) when in the normal rotational plane.
 6. A printing mechanism according to claim 5 wherein for each type bar (14) said tab extension (14b) is arranged relative to said arm extension such that in each operational position of the type bar (14), the tab extension (14b) projects out of the lower slotted disk (15b).
 7. A printing mechanism according to claim 2 wherein said means for acting on the free end (14a) of the selected type bars (14) include a guide ring (17) arranged around the periphery of the type bar assembly (3) and having an advance cam (17a) operating on the free end (14a) of the selected type bars (14) in the course of rotation of the assembly (3) to lift a selected type bar (14) into engagement with said cam portion (21).
 8. A printing mechanism according to claim 7 wherein said guide ring (17) is arranged above the plane of rotation of the type bar assembly (3), with the inside edge thereof extending over the free ends (14a) of the type bars (14), said guide ring (17) being provided with a cut-out portion (19) located diametrically opposite the printing point and which in the direction of rotation is provided with a deflecting member (20), said guide ring (17) being further provided with a recess (17d) which, respective to said cut-out portion (19), is staggered by approximately 90* opposite to the direction of rotation, said recess (17d) being covered by a restoring flap (17c) which is inclined in opposition to the direction of rotation.
 9. A printing mechanism according to claim 7 wherein said guide ring (17) further includes a follow-up cam (17b) operatively arranged relative to said advance cam (17a) in the direction of rotation and wherein said advance cam (17a) and said follow-up cam (17b) lie within the rotational range of the type bar free ends (14a) a predetermined rotational distance to either side of the printing point.
 10. A printing mechanism according to claim 9 wherein said cam portion (21) is arranged below the printing point and includes a printing cam (21a) and a resetting cam (21b) arranged relative to said printing cam (21a) in the direction of rotation, the cooperation of the type bars (14) with said guide ring (17) and said cam portion (21) being such that by the guiding of the type bar free ends (14a) on said advance cam (17a), the tab extension (14b) of each respective selected type bar (14) is brought into the rangE of the printing cam (21a).
 11. A printing mechanism according to claim 10, further including, an aligning cam means (23), positioned to precede in the direction of rotation the point of selection of the type bars (14), for lifting same a predetermined amount from the normal rotational position. 